Ball case, in particular for soccer balls

ABSTRACT

In a ball case consisting of two-dimensional blanks which are connected with each other at their edges, with the surface of the ball case having a pattern of two different groups of polygons, it is suggested for reducing the number of the two-dimensional blanks and for reducing the overall seam length to combine a first group of polygons consisting of three-armed star-shaped areas with a second group of polygons integrally formed from partial areas of one equilateral triangle and of three equilateral pentagons in such a manner that the pentagonal areas are situated at the points of the corners of the triangle and an imaginary corner and/or the centre of each of the pentagons lies on the perpendicular bisector of the opposite side of the triangle.

The invention relates to a ball case, in particular for soccer balls, which consists of two-dimensional blanks which are connected with each other at their edges, i.e. are sewed, bonded or welded, with the surface of the ball case having a pattern of two different groups of polygons, of which the first group consists of three-armed star-shaped areas, and several three-armed star-shaped areas in planar development contiguously forming a one-piece two-dimensional blank.

Ball cases of this known type are know from DE 37 26 830 C1 and EP 0 773 045 B1, for instance.

For manufacturing these known ball cases it is required to seam together 13 to 32 individual components (panels) or to connect these in any other way in order to obtain a ball case which is as spherically symmetrical as possible.

Apart from the work required for this which still is performed to a high degree by hand, which is arduous and results in an undesired and inconstant quality, the large number of individual blanks entails a considerable seam length because each edge of the usually pentagonal or hexagonal individual panels has to be sewn with a respective edge of an adjacent individual blank. The overall seam length thus increases with the number of panels.

The seams, however, are in many respects the weak points of the ball case which usually is made from leather, artificial leather, plastic laminates or textile composite materials:

1. It is the sewing thread which is particularly heavily strained and stressed, namely on the one hand by the interior pressure of a ball inflated with air or nitrogen, and on the other hand by the external mechanical load, as it occurs, for instance, in the field of professional soccer playing.

2. Each seam represents a deviation from the ideal spherical shape, i.e. causes an impairment of the roundness of the ball surface, which on the one hand results in an anisotropic wear behavior (the wear rate in the region of the seams is higher than in regions which are further away from the seams).

3. The seams of a ball have an effect on the spin of a “kicked” ball during free flight, comparable with the dimples of a golf ball which likewise have an effect on the flight behavior thereof.

4. It is due to fatigues of material of both the sewing thread and the leather or composite material, of which the individual blanks are made, that the circumference of the ball enlarges in the course of its lifespan as a result of interior pressure. Because of the spreading of the seams this effect is the stronger, the larger the overall seam length will be.

5. Moisture will penetrate through the seams into the interior of the ball, this resulting in undesired changes in terms of the weight as well as in terms of the behavior during flight and in game, and leads to premature wear, too.

The term “seam” is to be understood in the context of the present invention not only so as to include a conventional sewing seam, but also a bonded joint and a weld seam, depending on whether the two-dimensional blanks of the ball case have been sewn, bonded or welded with each other.

The invention is based on the object to provide a ball case which is suited for lowering the number of the panels to less than 13 and thus reduce the overall seam length, and with which one can concomitantly manage to approach the ideal spherical shape and improve the flight behavior and the wear resistance of the ball or ball case.

This object is met according to the invention with a ball case of the type initially mentioned in that the second group of polygons consists of polygons which are integrally formed from partial areas of one equilateral triangle and of three equilateral pentagons in such a manner that the pentagonal areas are situated at the points of the corners of the triangle and an imaginary corner and/or the centre of each of the pentagons lies on the perpendicular bisector of the opposite side of the triangle, which polygons are configured as separate, two-dimensional blanks.

Advantageous embodiments of the ball case according to the invention are characterized by the features of the sub-claims.

Those embodiments of the ball case according to the invention are particularly preferred in which the ball case consists of 8, 6 or only 5 two-dimensional blanks, namely 4 identical polygons of the second group in each case, and 4 or 2 identical one-piece blanks, most preferably, however, only one single one-piece blank, the blank(s) being composed of three-armed star-shaped areas.

The most advantageous embodiment of the ball case according to the invention is the “5 panel ball case” according to claim 5, which consists of 4 identical polygons of the second group and one single one-piece blank which is composed of 16 three-armed star-shaped areas.

It is preferred that the one-piece blank, which is composed of 16 three-armed star-shaped areas, has 6 terminal edges which are sewn, bonded or welded with each other in pairs such that the envelope of the blank (in the state connected with itself) is a sphere or has a three-dimensional shape which approaches the spherical shape as good as possible.

These terminal edges which are sewn, bonded or welded with each other in pairs, preferably have a right-angled contour, with the associated corners being not rounded so that the contours of the three-armed star-shaped areas, adjoining by connecting these edges, will have a continuous extension.

It is preferred that the corners of the equilateral pentagons and the corners, complementarily assigned thereto, of the three-armed star-shaped areas are rounded, because this will facilitate the connecting of the edges; such rounding, however, is not compulsory.

All two-dimensional blanks (panels) can be punched-out leather or artificial leather pieces; it is preferred, however, that they are cut-outs punched out from a multi-layered laminate or composite material which may include 4 layers or sheets permanently fixed to each other, in fact advantageously

a) a waterproof plastic coating layer defining the outer surface of the ball case,

b) a first foamed plastic layer,

c) a second foamed plastic layer and

d) a textile carrier layer impregnated with plastic material.

Here, the waterproof plastic coating layer may be a film of polyolefin or polyurethane, and also the first foamed plastic layer preferably consists of at least one thermoplastic polyolefin or polyurethane. It would also be possible that the waterproof plastic coating layer and the first foamed plastic layer are jointly introduced in the composite in the form of an integral foam film.

The second foamed plastic layer preferably consists of at least one elastomer which may be an elastomer on the basis of natural rubber or isoprene or silicone; such elastomer may also be a thermoplastic elastomer or thermoplast-elastomer-copolymerisate.

The ball case according to the invention is preferably used as ball case for soccer balls; it may also be used for other sport and game balls, however.

The invention will now be explained in further detail by means of the drawing:

FIG. 1 shows in a planar development a top view of 5 individual blanks or panels which, when they are connected with each other at their edges, form a spherical or almost spherical ball case according to the invention for use in a soccer ball;

FIG. 2 is an enlarged top view of a one-piece two-dimensional blank in the form of a polygon P₂ of FIG. 1.

In the preferred embodiment which is shown in the drawing, the ball case according to the invention consists of 5 two-dimensional blanks or panels which have been punched out from a suitable composite material. The 5 panels pertain to two different groups of polygons, of which the first group of polygons generally is referenced by P₁ and consists of three-armed star-shaped areas 11, 12. In the embodiment which is drawn in FIG. 1, 16 three-armed star-shaped areas 11, 12 contiguously form one single two-dimensional blank 10 made in one piece and having 6 terminal edges 4, 5, 6, 7, 8, 9 which have a right-angled contour and the associated corners of which, contrary to all other corners of the polygon blank 10, are not rounded.

For manufacturing the ball case the 6 terminal edges 4 to 9 are sewn or bonded with each other in pairs, i.e. edge 4 with edge 7, edge 6 with edge 8 and edge 5 with edge 9. If edges 4 to 9 are sewn or bonded with each other in pairs in the aforementioned fashion, then all three-armed star-shaped areas 11, 12 will be convexly curved in such a manner that the envelope of all three-armed star-shaped areas 11, 12 and, with this, of the one-piece blank 10 is a sphere or virtually spherically shaped. The one-piece blank 10 thus defines a skeleton of a spherical surface with 4 through-holes which will be closed by sewing on or sticking in a second group of polygons P₂.

The polygons P₂ are integrally formed from partial areas of one equilateral triangle 20 (FIG. 2) and of three equilateral pentagons 21 in such a manner that the pentagonal areas are situated at the points of the (imaginary) corners of the triangle and an imaginary corner E and/or the centre M of each of the pentagons 21 lies on the perpendicular bisector 22 of the opposite side of the triangle. The polygons P₂ of the second group of polygons are likewise shaped as separate, two-dimensional blanks as the polygon(s) of the first group P₁, the polygon(s) being realized in the drawn embodiment by the single one-piece blank 10. The corners of the equilateral pentagons 21 are rounded, just as the corners, complementarily assigned thereto, of the three-armed star-shaped areas 11, 12.

In the embodiment which is drawn in FIG. 2, the centre M of the pentagons 21 lies within the area of the triangle 20; it would also possible, however, that it is located outside the triangle area, which is readily apparent for a person skilled in the art.

Although less preferable, the one-piece and two-dimensional blank 10 formed from the three-armed star-shaped areas 11, 12 can be cut into 2 or 4 congruent parts which, however, will have to be connected with each other again for manufacturing the ball case according to the invention, in fact along the cutting lines 1, 2 and/or 3. In case the one-piece blank 10 is severed along cutting line 1, one obtains 2 two-dimensional blanks (A+B) and (C+D) which can be brought to congruence by rotating one of the two sections, i.e. they are congruent. If one of the so produced two sections is again severed along cutting line 2 or along cutting line 3, there again will be formed 2 sections from each half, namely sections A, B, C and D which are congruent to each other. In case one would again sever the so produced sections A to D along the lines 13, one would receive in each case 3 congruent three-armed star-shaped areas 12 and one three-armed star-shaped area 11.

The advantages achieved with the ball case according to the invention which manifest the more, the less the number of panels will be which are used in the respective embodiment, are the reduced seam length compared with prior art, the wearing resistance resulting from this, the reduced water absorption, the reduction in the manual work required for connecting the edges of the two-dimensional blanks and the lower disposition to fatigue of material, the latter again being a consequence of the reduced seam length and the reduced water absorption.

Totally unexpected for a person of ordinary skill in the art, however, are the following additional advantages, i.e. an improved spin and a superior flight behavior of the balls produced from the ball case according to the invention; these properties will have the largest effect if the ball case is used for soccer balls. It could be found indeed that the specific geometry of the two different groups of polygons, and the fact that the two-dimensional blank 10—most notably if it is made in one piece, but also in case it is composed of 2 or 4 parts—will result in an integrally contiguous skeleton on a spherical surface, improving the restoring capability of the area which is struck during kicking off the ball or during an impact thereof, thus resulting in a lower energy dissipation as a result of the physical work required for deforming the ball case. A lower energy dissipation during kicking off a ball, however, means that the amount of kinetic energy available for the free flight of the ball is larger, and that the spin which has been given to the ball during kicking off remains unchanged for a longer period. The latter, in turn, enhances the unerringness of a kicked-off ball and reduces the risk of any unwanted drifting of a kicked-off ball.

Finally, the particular geometry of the two different groups of polygons allows the use of sewing machines for a portion of the overall seam length to be sewn which is larger than was the case with the conventional ball case with 13 or even 32 panels, with the rounding of the corners of the panels particularly complying with the use of sewing machines.

A further advantage of the one-piece and two-dimensional blank 10, defining a skeleton which completely encompasses the spherical surface, is a clear improvement of the roundness of the ball case or ball in the inflated state. 

1-13. (canceled)
 14. A ball case consisting of two-dimensional blanks which are connected with each other at their edges, the surface of the ball case having a pattern of two different groups of polygons, of which a first group consists of three-armed star-shaped areas, and several three-armed star-shaped areas in planar development contiguously forming a one-piece two-dimensional blank, wherein a second group consists of polygons which are integrally formed from partial areas of one equilateral triangle and of three equilateral pentagons in such a manner that the pentagonal areas are situated at the points of the corners of the triangle and an imaginary corner and/or the centre of each of the pentagons lies on the perpendicular bisector of the opposite side of the triangle, said polygons being configured as separate, two-dimensional blanks.
 15. The ball case according to claim 14, consisting of 20 two-dimensional blanks, namely 4 identical polygons of the second group and 16 blanks in the form of three-armed star-shaped areas.
 16. The ball case according to claim 14, consisting of 8 two-dimensional blanks, namely 4 identical polygons of the second group and 4 identical one-piece blanks which each are composed of 4 three-armed star-shaped areas.
 17. The ball case according to claim 14, consisting of 6 two-dimensional blanks, namely 4 identical polygons of the second group and 2 identical one-piece blanks which each are composed of 8 three-armed star-shaped areas.
 18. The ball case according to claim 14, consisting of 5 two-dimensional blanks, namely 4 identical polygons of the second group and one single one-piece blank which is composed of 16 three-armed star-shaped areas.
 19. The ball case according to claim 18, wherein the one-piece blank has 6 terminal edges which are connected with each other in pairs.
 20. The ball case according to claim 18, wherein the one-piece blank has 6 terminal edges which are connected with each other in pairs and have a right-angled contour with its associated corners not being rounded.
 21. The ball case according to claim 14, wherein the corners of the equilateral pentagons and the corners, complementarily assigned thereto, of the three-armed star-shaped areas are rounded.
 22. The ball case according to claim 14, wherein all two-dimensional blanks are cut-outs punched out from a multi-layered composite material.
 23. The ball case according to claim 14, wherein all two-dimensional blanks are cut-outs punched out from a multi-layered composite material with said composite material comprising: a) a waterproof plastic coating layer defining the outer surface of the ball case, b) a first foamed plastic layer, c) a second foamed plastic layer and d) a textile carrier layer impregnated with plastic material.
 24. The ball case according to claim 23, wherein the first foamed plastic layer comprises at least one of a thermoplastic polyolefin and a polyurethane.
 25. The ball case according to claim 23, wherein the second foamed plastic layer comprises at least one elastomer. 